Friday, September 11, 2015

The Delphi Technique: Making Sense Of Consensus


The Delphi technique is a common method used to gather data from a variety of different professional fields, and is designed to achieve a convergence of opinion on a specific issue through group communication. This technique is well suited as a method for consensus-building by using questionnaires delivered by multiple iterations to collect data from participants. Participant selection, time frames for conducting and completing the study, the possibility of low response rates, and unintentionally guiding feedback from respondent groups are issues that need to be accounted for when using the Delphi method.

The Delphi technique was originally designed by Dalkey and Helmer at the Rand Corporation in the 1950s in order to solicit data on specific issues for the purpose of goal setting, policy investigation, or predicting the occurrence of future events. According to Delbecq, Van de Ven, and Gustafason (1975), the Delphi technique can be used to achieve the following objectives: 
1.      Determine or develop a range of possible program alternatives.
2.      Explore or expose underlying assumptions or information leading to different judgments.
3.      Seek out information which may generate a consensus on the part of the respondent group.
4.      Correlate informed judgments on a topic spanning a wide range of disciplines.
5.      Educate the respondent group as to the diverse and interrelated aspects of the topic.

Unlike other data gathering techniques, the Delphi technique utilizes multiple iterations (feedback processes) designed to develop a consensus on a specific topic. The feedback process allows and encourages all participants to reassess their initial judgments about the information provided in previous iterations. Other characteristics of the technique is the ability to provide anonymity to respondents, a controlled feedback process, and the suitability of a variety of statistical analysis techniques to interpret the data.
1.      Anonymity is one of the strongest characteristic and advantage of the technique, as it prevents stronger personalities from drowning out timid individuals, and prevents coercion and manipulation.
2.      Controlled feedback is designed to reduce the effect of common communication that occurs during group discussions that derails the original purpose of the discussion.
3.      Statistical analysis techniques ensures each opinion is represented equally after each iteration, and reduces pressure to succumb to group conformity.

The Delphi Process
The Delphi technique can be employed until a consensus is reached, however, several researchers indicate 3 iterations are sufficient to collect information and reach consensus in most scenarios. The following guidelines show 4 rounds in order to present an example of the process when more data is needed. 

Round 1: The technique begins with an open-ended questionnaire that serves as the cornerstone of gathering information about a specific topic from the participants. After the investigators (facilitators) collect each participant’s responses, a well-structured questionnaire is created. The well-structured questionnaire is used as the survey in round 2.

Round 2: Each participant receives a second questionnaire, and reviews the topics summarized by the investigators. The summarizations are based off the information the participants provided in the first round. The participants also rate or order each topic in order to establish priorities. The process of establishing priorities identifies agreements or disagreements among the participants. 

Round 3: Each participant receives a third questionnaire that includes all the topics and ratings summarized from the previous round. The participants are asked to revise their judgements, or specify why they won’t change their answers. 

Round 4: In the final round, each participant receives another questionnaire with the remaining topics, ratings, minority opinions and topics that reached a consensus. 

The most important process of the Delphi technique is selecting participants. According to various researchers, the three groups most qualified to be participants in a Delphi method are:
1: Top management decision makers who will utilize the outcomes of the Delphi study.
2: Professional staff members together with their support team.
3: Respondents to the Delphi questionnaire whose judgements are being sought.      

Though the Delphi technique is used regularly in various professional settings, it seems to be extremely situational. One of the many elements that are needed to ensure the Delphi technique is employed properly is time. Depending on the number of the participants and the data being evaluated, it may take several days or even weeks to complete the technique. Other methodologies can be used in place of the Delphi technique that would likely result in the same quality of information, but with less time. The technique also has other potential shortcomings, like low response rates, which have to be accounted for. Striking a balance between the requested data, number of participants and timeframe, appears to be key element when deciding to utilize the methodology.

Hsu, Chia-Chien & Sandford, Brian A. (2007). The Delphi Technique: Making Sense of Consensus. Practical Assessment Research & Evaluation, 12(10). Available online:


  1. You mention one of the most important elements needed to ensure the technique is employed properly is time. Does the article identify an ideal amount of time for the Delphi technique to work most effectively?

  2. The author states that the timeframe necessary to employ the technique effectively varies depending on how many people are participating. Thus, the timeframe needs to be evaluated before the technique is used for two reasons: to ensure everyone can participate until the technique is completed, and the information that is pursued doesn’t have a suspense date. In essence, there isn’t a specified amount of time the Delphi technique needs to be effective, as long as the purpose of technique is accomplished while controlling for the variables mentioned in the article. My critique of the Delphi technique is that sometimes it may take too long to complete, and during the time Delphi is being employed, other techniques can be used that take up less time.

  3. It's interesting this study used 3 rounds, much of the others I've seen used only 2. I do think it's better to use 3 if you have the time and resources to do so.

    1. 3 rounds is usual how long the technique lasts, 2 rounds seem short as it doesn't allow the participants to change their answers or provide reasoning why they won't change their mind.

  4. Well stated. You mentioned that time to implement this technique was one of it's key weaknesses. I would also say that the preparation of the data and questions is also a challenge. When developing our example scenario, we found it rather difficult to apply this technique without a data set.